Sewing machine presser-foot automatic control attachment



July 31, 1951 I A. CHICKETTI 2,562,771

SEWING MACHINE PRESSER-FOOT AUTOMATIC CONTROL ATTACHMENT Filed May 6, 1950 INVENTOR. C'H/CKETT/ A TTOENE' Y5 Patented July 31, 1951 UNITED STATES PATENT OFFICE SEWING MAcHINEPREssER-FooT AUTO- MATIC CONTROL ATTACHMENT Antonio Chicketti, Seattle, Wash.

Application May 6, 1950, Serial No. 160,452

1' This invention relates to attachments for sewing machines generally of the type used in sewing leather and other heavy materials, and is specifically directed to an improved attachment operable to efiect retraction of the sewing machine presser-foot automatically in synchronism with reciprocation of the needle-bar, much after the fashion of the attachment disclosed inthe Beckwith Patent No. 1,280,947. By reciprocating the presser-foot up and downin this'manner, the work may be shifted manually in the intervals between stitches so thatherring bone and other special'types of stitching maybe accomplished with a direct or simple feed sewing machine.

An object of my invention is to provide an attachment of this type, having a control element which can'be shifted at will into and fromoper ative position more easily and quickly than with any previous attachment of a similar type known to me. This advantage is achieved in part by avoiding delays encountered in releasing and tightening clamp screws or similar control element holding devices present in the prior art, before and after such shifting movements of the control elementare executed.

Another object is to provide such an attachment in which the control element cannotslip out of its operative position despite any normal vibrations or jarring present during operation of the sewing machine and yet which can very 7 Claims. (o1. 112- 239) readily be moved into inoperative position b'ya I bar or other reciprocable element carrying the presser-foot, and a control element carried by a pivotal support on such mounting forswinging about an axis generally transverse to the line'of reciprocation of the presser-foot. When swung on its pivot into operative position such control element slidably engages a guide extending parallel to the line of reciprocation of the presserfoot. Preferably such engagement takes 'place between. a control element key projection and a groove in the side of the sewing machine head.

When the control element is swung into operative position, the key comes into registry with such groove. A loaded spring acting onthe control element causes its: key to snap sharply into the 2 groove where it is held until deliberatelyremoved therefrom by the operator. I} I Preferably the control element comprises an elongated member apertured at an intermediate location thereon to engage and pivot on ahorizontal pin projecting from the attachment mounting. Such apertureis slightly enlarged or elongated in cross section relative to the pivot pin topermit the control element to be rocked slightly in a plane containing its normal pivot axis. The locating key comprises a lateral projection on the lowerend of the control element. A coil spring reactin from a footing or enlargement on the outer or projecting end of the pin presses the con trol element toward the sewing machine head to maintain the key in the groove therein.

These and. other features, objects and advantages of my invention, including certain details of construction of its preferred form will now be made more apparent by the following detailed description thereof based on the accompanyin drawings.

Figure 1 is a perspective view of the improved attachment.

Figure 2 is an end elevation view of=the same as installedon one typical make of sewingma chine for which the attachment is adapted; many portions and details of the sewing machine being omitted for convenience in illustration.

Figure 3 is a perspective view of a slightly modi fled form of the attachment, as mounted on the head of a similar type of sewing machine which is slightly modified for the purpose. I

Referring to Figures 1 and 2, the sewing machine needle-bar I0 and the parallel bar' IZ carrying the presser-foot I4 at its lower end are guided for vertical sliding movement-in thesewing machine head. I 6, located as show'n abov e the usual work-supporting horn l8 which houses the feed dog (not shown). As shown best in Figure 3; the needle-bar is reciprocated up and down by the usual walking beam 20 pivotally connected to the upper end of such needle-bar. A crosshead 22 is'centr'ally apertured for free sliding thereof over the needle-bar. This crosshead is connected by one end to the upper end of the presser-foot supporting bar [2, and at itsother end apertured to slideover the stud 24 projectingupward from the head [6; The upper end of this stud is threaded and carries a stop nut 26. A coil spring 28 encircles the stud to urge the crosshead 22 downwardly. The presser-foot thenpresses the'work firmly against the horn l8. Suitable means (not shown) are usually provided for raising the presser-foot l2 from the workat will,

spring 28 yielding to permit such retraction of the presser-foot.

As will be evident, reciprocation of the presserfoot may be effected in synchronism with the needle-bar simply by raising the presser-ioot as the needle-bar ascends, and allowing the presserfoot to be lowered by reaction of spring 28, as the needle-bar descends. This type of action is accomplished by' my improved attachment which derives motion from the sewing machine mechaniSm operating the needle-bar.

The attachment mount or support comprises a T-shaped metal piece 30, the arms of which are apertured. One end of a clamp'band 32 is loosely connected to one of these arms by a rivet 34 which passes through the arms aperture. The opposite arm is detachably connected by a bolt 35 and nut 38 to the correspondingly opposite end of the clamp band 32. The central portion of the clamp band is bowed away from the mounting element 30 to provide a clamp opening which receives the upper end of the presserfoot supporting bar l2, as shown. When the mount is clamped tightly over the bar [2, the stem or shank of the T-shaped element 30 is disposed upright as shown.

The element 30 is formed with its shank portion ofiset outwardly from the plane of its arms. A pin 40 extends through an aperture in the shank and projects horizontally outward from the element 30. Both ends of the pin are headed. Between the projecting end of the pin and the element 30 is received a coil spring 42 which encircles the vpin and presses against its headed outer end in the sense away from the mounting element. The apertured control element 44 of the attachment is pivotally and slidably supported by pin 40, being normally pressed by spring 42 against the outer face of the shank of mounting element 30. The control element aperture is slightly enlarged or elongated relative to the pins cross section to permit rocking of such control element in a plane containing the pins axis.

The control element 44 comprises an elongated strip 01' metal which is substantially vertical in the operative position of such element. The upper end of this control element strip is turned inward and projects over and into the path of vertical reciprocation of the end of the walking beam 20 pivotally; connected to the needle-bar ID, to be contacted and raised by one or both of these moving parts on their upward travel, thereby to elevate the presser-foot. The lower end of such control element is also turned inward. A locating element 46 projects from such lower end and constitutes a slide key engageable in a vertical slot 48 formed in the side of the sewing machine head l6, for the purpose of maintaining alignment of the control element with the upper end portion of needle-bar II]. By such key and slot engagement, maintained by the resilient force of spring 42, the control element is eil'ectively locked in its vertical or operative position. Because the springs holding force is constant, the control element cannot be jarred out of operative position by machine vibrations, or the like. There are no holding elements to work loose by jarring and vibrations as in the prior art.

As previously mentioned, the pin-receiving aperture in control element 44 is somewhat oversize relative to the pin, and thereby enables limited rocking of the control element on the pin in a plane which contains the axis of such pin. When the control elementoccupies its vertical or operative position shown in Figure 2 it may be rocked at will in the vertical plane of the pin, and its lower end thereby swung out of engagement with guide slot 48 against the force 01' spring 42. After being disengaged from the groove 48 in that manner the control element may then be swung about the axis of pivot pin 40 into an inoperative position with its upper end removed from the path of reciprocation of the needle-bar's upper end. Actually both such phases of this inactivating movement of the control element are readily executed with a single quick flip of the hand.

When the control element is swung back toward operative position, about the axis of pin 40, its lower end or projection key 46 first contacts and is then cammed outward by the curved surface of the cylindrical sewing machine head l6. As the control elements lower end is progressively deflected outward during its approach toward groove 48, the spring 42 is correspondingly compressed more greatly. When the projection 46 reaches a position of registry with the groove it is then snapped sharply into the same by the stored energy in the spring, and the operator is immediately aware that the control element is in operative position. Such activating movement of the control element is readily accomplished by a quick and direct hand movement.

The simple modification shown in Figure 3 results in a slightly different arrangement for engaging the control element to impart reciprocating motion to the presser-foot. In this case the laterally projecting upper end portion of the control element 44 is somewhat shortened so that it does not project directly over the needle-bar HI. Instead it is engaged by an elongated abutment pin 50 which also serves as the pivotal connection between the upper end of the needle-bar and the swinging or drive end of the walking beam 20, as shown in Figure 3, such pin replacing the usual shorter pin interconnecting these elements as shown in Figure 2. The foregoing and still other equivalent arrangements for actuating the control element for drive purposes will be evident to those familiar with this art.

With the concept of my invention illustrated as by the examples shown and described above, it will be evident that certain modifications may be made in the form of the novel attachment without departing from the essentials of the present invention.

I claim as my invention:

1. In combination with a sewing machine having a presser-foot supporting bar guided for vertical reciprocation in the sewing machine head, means on said head normally urging the presser-foot downward against the work, but yieldable upwardly therefrom, and needle-bar reciprocating drive mechanism, an attachment comprising support means fixedly carried by the presser-foot supporting bar for reciprocation therewith, a control element, pivot means carried by said support means and supporting said control. element therefrom for swinging about a generally horizontal axis through an angle between operative and inoperative positions, said control element having a projecting portion extending over and into the path of upward movement of a reciprocating part of said drive mechanism, in the operating position of such element, to be engaged by such part for raising said sup-- porting bar synchronously with the needle-bar, said control element further having a second projecting portion constituting a slide. key, vertical guid means. carried by the sewing machine head and slidably engageable by said slide key in the operative position of said control element for retaining said control element against swinging on its pivot axis during reciprocation thereof, but disengageable by retracting movement of said slide key in a direction generally parallel to said horizontal pivot axis, and spring means carried by said support means and urging said slide key normally into engagement with said guide means in the operative position of said control element, but yieldable to permit retraction of said slide key therefrom, thereby to permit swinging of said control element about said horizontal axis and into inoperative position.

2. The combination defined in claim 1, wherein the pivot means comprises a pivot pin projecting horizontally from the support means and through an aperture in the control element, said aperture being somewhat oversized relative to the pin to permit limited swinging of such control element in a plane containing such axis for retraction of the slide key from the guide means, the latter comprising a grooved member fixed in relation to the sewing machine head.

3. The combination defined in claim 2, and further wherein the resilient means comprises a coil spring encircling the pivot pin and pressing the control element lengthwise of such pin for maintaining the slide key in the groove.

4. A sewing machine attachment for operating the sewing machine presser-foot in synchronism with the needle-bar, said attachment comprising a support adapted to be fixed on the upper end of the presser-foot supporting bar of the sewing machine, a cantilever arm projecting outward substantially horizontally from said support, an elongated control element transversely apertured to slide on said cantilever arm lengthwise of such arm, a spring urging said control element normally against said support, but yieldable to permit separation of said control element therefrom, said control element having at one end a lateral projection adapted to extend over and into the path of upward movement of a reciprocating part of the needlebar drive mechanism of the sewing machine when said control element is operatively positioned against said support, thereby too effect raising of the presser-foot with the needle-bar, yielding of said spring permitting retraction of said control element along said cantilever arm away from said support, and means cooperating with said cantilever arm and said control element in retracted position for guiding said control element into inoperative position thereof out of the path of said reciprocating part.

5. A sewing machine attachment for operating the sewing machine presser-foot in synchronism with the needle-bar, said attachment comprising a support adapted to be fixed on the upper end of the presser-foot supporting bar of the sewing machine, a pivot pin projecting outward substantially horizontally from said support, an elongated control element transversely apertured to pivot and slide on said pivot pin, and a coil spring encircling said pivot pin and urging said control element normally against said support, but yieldable to permit separation of said control element therefrom, said control element having at one end thereof a lateral projection adapted to extend over and into the path of upward movement of, a reciprocating part of the needle-bar drive mechanism of the sewing machine when said control element is operatively positioned, disposed substantially vertical and against said support, thereby to effect raising of the presser-foot with the needle-bar, said control element further having a second lateral projection constituting a slide key adapted to be pressed by action'of said spring on said control element into engagement with vertical guide means carried by the sewing machine head, when the control element is operatively positioned, thereby to maintain the control element in said operative position during reciprocation thereof effected by the needle-bar drive mechanism, yielding of said spring permitting retraction of said control element away from said support and disengagement of said slide key from said vertical guide means to enable rotation of said control element on the axis of said pivot pin and into inoperative position out of the path of movement of said reciprocating part.

6. The sewing machine attachment defined in claim 5, wherein the control element aperture is oversize in relation to the pivot pin to permit limited tilting of said control element in a plane containing the axis of the pivot pin.

7. A sewing machine attachment for operating the sewing machine presser-foot in synchronism with the needle-bar, said attachment comprising a support adapted to be fixed on the upper end of the presser-foot supporting bar of the sewing machine, a pivot pin projecting outward substantially horizontally from said support, an elongated control element transversely apertured to pivot and slide on said pivot pin, and a coil spring encircling said pivot pin and urging said control element normally against said support, but yieldable to permit separation of said control element-therefrom, said control element having at one end thereof a lateral projection adapted to extend over and into the path of upward movement of, a reciprocating part of the needle-bar drive mechanism of the sewing machine when said control element is operatively positioned, disposed substantially vertical and against said support, thereby to efiect raising of the presser-foot with the needle-bar, and locating means engageable by said control element when operatively positioned, and efiective by such engagement to maintain said control element vertical, said spring urging said control element into engagement with said locating means but yieldable to permit retraction of said control element therefrom, thereby to permit rotation of said control element about said pin into inoperative position swung away from the vertical.

ANTONIO CHICKETTI.

No references cited. 

